The invention relates to media bearing invisible encodements that may be edited and read employing a reader, and particularly to methods and apparatus employing a hierarchy of invisible dyes for recording multiple encodements over one another on the media to enable selective editing, each invisible dye rendered visible to a reader under differing applied wavelengths of light, whereby the invisible encodements may be selectively captured, decoded and reproduced as data, sound or visual information and methods of producing the same.
It is well known to imprint data on various articles and objects, including printed media, labels, containers, vehicles, etc., in the form of a machine readable, code or xe2x80x9csymbologyxe2x80x9d that is visible to the eye but requires a reader to read and decode. The terms xe2x80x9csymbologyxe2x80x9d or xe2x80x9csymbologiesxe2x80x9d are generally employed to denote spatial patterns of symbology elements or marks, wherein each mark has a shape and separated from an adjacent mark by a spacing between the marks, whereby information is encoded in the shapes and/or the spacings between the marks, and embrace bar codes and other codes as described further below. Typically the decoded information output by the reader is used by a machine in a process of identification of the article and to associate it with other data, e.g. unit price and restocking code, which may be displayed and printed out. A great many symbologies and specialized symbology readers have been adopted over the years.
It is also known to encode aural information as such machine readable bar codes associated with images on media so that the aural information or sound can be reproduced from the encoded symbology. Such systems are shown, for example, in U.S. Pat. Nos. 5,276,472 and 5,313,235 in relation to photographic prints, and in U.S. Pat. Nos. 5,059,126 and 5,314,336 in relation to other objects or printed images.
Furthermore, it is well known to record or print symbologies or human recognizable images on various media, e.g., documents, identity cards, financial instruments, professional photographic prints, etc., to verify identity or inhibit unauthorized use or copying, and on stamps and envelopes in postal cancellation applications. Such printing is typically done with one or more invisible ink or dye imprinted on the surface of the document or incorporated into internal layers of the media. These symbologies or recognizable images are normally invisible but can be made visible to and read by a scanner or reader when illuminated by a specific light wavelength or band, e.g. infrared and ultraviolet wavelengths. The printed invisible symbologies or images can be made with a single invisible material sensitive to a single light wavelength or two printed invisible encodements or images can be with two invisible materials, wherein each material is sensitive to a separate light wavelength as described, for example, in U.S. Pat. No. 5,525,798. Such symbologies or images are intended to be permanently recorded or printed onto or incorporated within the media and to be tamper resistant.
The above-referenced, commonly assigned and pending patent applications disclose recording xe2x80x9cvariable dataxe2x80x9d as an invisible xe2x80x9cencodementxe2x80x9d of a selected symbology located in an image field on media on a photographic print image or a print that is produced by other means. The term xe2x80x9cvariable dataxe2x80x9d includes data that varies from print to print and contains information related to the visible print image. The xe2x80x9cencodementxe2x80x9d is preferably formed of a two-dimensional symbology that is relatively dense and is at least co-extensive in area with the visible photographic image to maximize the amount of sound information that can be recorded. The encodement is invisible or substantially invisible to the human eye when viewed under normal viewing conditions, that is, facing the viewer and under sunlight or normal room illumination such as incandescent lighting. This ensures that the encodement does not materially degrade the visible print image.
A number of encodement materials and encodement printing techniques are disclosed in the above-referenced commonly assigned and pending patent applications. It is contemplated that the preferred encodement materials would be infrared absorbing dyes imprinted onto the visible print image using thermal printing or inkjet printing techniques. The user that receives such a print with the invisible encodement made by a photofinisher or that prints an encodement onto visible print image would employ a playback unit, e.g., a hand held reader, to capture the encodement and reproduce or play back the sound or display the visual information or otherwise use the variable data of the encodement.
It is also contemplated that the information that is to be encoded into the invisible encodement includes camera recorded information and user recorded information that is recorded on a filmstrip at the time that a filmstrip image frame is exposed in the manner described in the above-referenced ""472 patent for example. This use of invisible encodements overlying the print image advantageously increases the area in which the encodement can be recorded beyond the border or back side of the print shown in the ""472 patent. It is further contemplated that the invisible encodements will be printed over or with the visual image at the time that prints are made from the filmstrip image frames. Typically, such prints would be made for consumers (hereafter referred to as users) from such filmstrips having the capability to record sound and camera information by photofinishers.
In addition, digital cameras are available that capture digital image data when used and also have the capability of recording user input sound information and camera input exposure information at the time the image is captured by the user. Software implemented typically in a personal computer is employed to process the digital image data and display the images on a monitor for editing and to make permanent prints of such digitally captured images employing inkjet or laser color printers. There is a need for a method and apparatus for printing such an invisible encodement on a visible print image that is made using the printer coupled to the personal computer.
This need also exists in other contexts where the user desires to generate information independent of the digital camera input information or information that is already on a print provided by a photofinisher and to print it as an invisible encodement on the visible print image. For example, the user of such a system may obtain a digital image file from another source than a digital camera, e.g., from an Internet source or by scanning an image. In this context, there is also a need for a method and apparatus for printing such an invisible encodement on a visible print image that is made using the printer coupled to the personal computer.
These needs cannot be met by simply writing over the existing invisible encodement using the same wavelength absorbing or fluorescing ink or dye (e.g., an infrared absorbing dye) without introducing further errors in reading and reproducing the encoded sound or visual information. Interference of the newly recorded encodement over the existing encodement would occur unless the existing invisible encodement is removed or rendered so faint that it does not exceed a noise threshold of the imager. It would not be practical for the user to remove or render the existing encodement that faint, because of potential damage to the visible print image and the inability to accurately gauge that the removal or rendering has been effective, since it is invisible to the eye.
It is also impractical to write over the existing invisible encodement using a higher concentration or greater laydown of absorbing or fluorescing ink or dye than the earlier recording and relying on the difference in absorbency or fluorescence to only read the later, more concentrated material. It would be necessary to define a threshold for the reader that would effectively mask or ignore the lower absorbance or fluorescence levels that are sensed, which would be difficult to define accurately enough to avoid mistakenly masking or ignoring a correct but low concentration encodement. The encodement would not be found or would be read incorrectly if only parts of it exceeded the threshold. Also, such dyes and inks tend to be come visible to the eye as the concentration that is printed on media is increased. Given the difficulties with visible absorbency of infrared and fluorescent dyes, and the relatively low maximum contrast achievable, this is not a practical solution.
The invention is defined by the claims. The invention, in its broader aspects, provides: (1) a print media having a visible image and a plurality of invisible encodements comprising data printed over it in a hierarchy order, wherein the encodement of the highest order represents a replacement or edited version of the data of lower order encodements; (2) apparatus and methods for effectively editing an existing invisible encodement printed on media with a material sensitive to a first light wavelength by printing an edited or replacement encodement over it with a material sensitive to a second light wavelength of higher order in the hierarchy; and apparatus and methods for selectively reading the highest order encodement, all of the encodements or selected ones of the encodements.
The editing capability is preferably provided using multiple wavelength materials, e.g., dyes or inks, in printer containers available for use with conventional consumer use printers and a reader capable of selectively capturing and decoding encodements printed with materials sensitive to multiple distinct wavelengths of light. A hierarchy of distinct wavelength sensitive, invisible print materials is established for printing the initial and multiple subsequently printed encodements. When illuminated by a predetermined illumination wavelength of the hierarchy, the symbology of each encodement fluoresces at a further predetermined wavelength or absorbs the illumination wavelength.
The reader is supplied with multiple encodement illumination light sources or filters for a single broad band light source to illuminate the encodements on the media with the hierarchy of illumination wavelengths. The reader is also supplied with an array of light sensitive elements that are selectively rendered sensitive to the illumination wavelengths of the hierarchy, in the case where light absorbing materials are used to print the encodements, or sensitive to the fluorescent wavelengths of the hierarchy, in the case where fluorescing materials are used to print the encodements.
The reader can be sequentially operated to render the light sensitive elements sensitive to the hierarchy of illumination or fluorescing wavelengths either automatically in a predetermined sequence or selectively upon the initiative of the user. The reader captures and decodes the selected one or all encodements and plays back the decoded sound or displays the decoded visual information or otherwise employs the variable data. Alternatively, the reader automatically determines the most recently recorded encodement as a function of the established hierarchy and decodes and plays back or displays that information only. The reader can also advise the user of the number and wavelengths of the encodements that are detected in this process.
Theoretically, invisible print materials sensitive to a large number of wavelengths can be employed in the hierarchy. However, for simplicity, the user can be provided with just one further wavelength sensitive print material in a suitable printer container for home use in editing encodements printed by a photofinisher on photographic prints.
It is an advantageous effect of the invention that the user that initially records an invisible encodement on a print or receives a print with an encodement printed by a photofinisher or from another source is provided with the capability of editing the invisible encodement while preserving the print that it is recorded on. The invention provides that such invisible encodements that are not pleasing or are printed in error or that have degraded due to exposure or handling to the point where reproduction quality is impaired can in effect be written over. This is of great advantage for the instances in which an archival print which may not be able to be reproduced to the same image quality has been encoded erroneously. Where the data captured in a digital or conventional photographic camera is automatically recorded on the prints made by a photofinisher as an invisible encodement, there would often be a desire to customize or edit the data at a later time. Similarly, the user may desire to customize or edit the data and print a further invisible encodement over previously printed invisible encodements on a visible print image that the user has previously printed or obtained from another source than a photofinisher. The invention provides a high degree of flexibility and choice in printing invisible encodements on a visible print or on other media.